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Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Andalas Kampus Universitas Andalas Limau Manih Padang 25163
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INDONESIA
Jurnal Riset Kimia
Published by Universitas Andalas
ISSN : 1978628X     EISSN : 24768960     DOI : -
Core Subject : Science,
Chemistry
Arjuna Subject : -
Articles 554 Documents
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Pengaruh Pemberian Variasi pH terhadap Produksi Trigliserida Total dan Komposisi Asam Lemak dari Chlorella Vulgaris Air Tawar Wulandari, Rahmadani; Dharma, Abdi; Syafrizayanti, Syafrizayanti
Jurnal Riset Kimia Vol 10, No 2 (2019): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v10i2.316

Abstract

Chlorella vulgaris is a microalgae that has high lipid content and potential as raw material for biofuel production. This study aims are to determine the effect of pH on growth, lipid production and fatty acid composition of C. vulgaris by using Growmore 32-10-10 fertilizer as a culture medium. Microalgae were cultured in medium Growmore 32-10-10 for 10 days. Afterward, pH of medium was varied into pH 5, 7, 8.2 and 9 and continued cultivate for 3 days. C. vulgaris cultured at pH 8.2 which is a control pH reached optimum growths. The GC-MS analysis for lipid productivity of C. vulgaris was 0.5020 g/L/day and 0.2902 g/L/day for microalgae grew at pH 8.2 and 9, respectively. Cultures at pH 8.2 and 9 produce methyl hexadecanoate, methyl 9-octadecanoate, methyl octadecanoate, methyl 9,12-octadecadienoate, methyl 9,11-octadecadienoate. Additional fatty acid methyl nonadecanoate was also found in C. vulgaris grew at pH 9. The low and high pH stress of C. vulgaris culture medium did not affect culture growth but altered lipid production and fatty acid composition.
Sintesis Senyawa Aurivillius Lapis Empat PbBi4Ti4O15 dan PbBi3NdTi4O15 dengan Metode Lelehan Campuran Garam NaCl-KCl dan Karakterisasi Struktur Wibowo, Gita Rachmad; Emriadi, Emriadi; Zulhadjri, Zulhadjri
Jurnal Riset Kimia Vol 10, No 2 (2019): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v10i2.307

Abstract

Four-layered Aurivillius phases PbBi4Ti4O15doped with Nd3+ with formula PbBi3NdTi4O15 were synthesized by molten-salt technique using NaCl and KCl (1:1 molar ratio) as the flux. Precursors were weighed stoichiometrycally and grinded with salts mixture in 1:7 ratio (product : salts mixture) until homogenous. The samples were heated at temperature 600oC, 700oC, 800oC, and 900oC for 5 hours for each temperature. The products were characterized by X-ray diffractometer (XRD), Scanning Electron Microscope (SEM) and LCR-meter. XRD data were refined by Rietica program using Le Bail technique. Refinement results showed the best structure as the A21am of space group for both samples. Surface analysis for each samples morphology is the plate-like by SEM characterization. Dielectric constants measured at room temperature show that the sample doped Nd3+ has lower value than sample without containing Nd3+ cation.
Uji Aktivitas Sitotoksik dan Antibakteri Ekstrak Daun Tumbuhan Rengas (Gluta renghas L) Ibrahim, Sanusi; Suryati, Suryati; Aziz, Enda Desriansyah
Jurnal Riset Kimia Vol 11, No 1 (2020): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i1.345

Abstract

Generally, Gluta renghas L. is known because of its very toxic latex which can cause hard irritations to skin. Although, rengas latex has efficacy as an antibacterial agent. Related to previous research, it has been reported that there are urisol, rengol, glutarengol, laccol, and thitsiol in rengas latex. The woody trunk was reported to contain flavonoid, benzenoid, lipid, and steroid compounds. The leaves, were reported shows that the leaves of G. renghas contain an anticholinesterase substance and can be reduced the rate of hydrolysis of acetylcholine. Extraction of rengas leaves has been carried out. It has been shown phenols, steroids, and coumarins compounds in methanol extract, flavonoids, phenols, saponins and alkaloids compounds in ethyl acetate extract, steroids and alkaloids compounds in hexane extract. In the present, cytotoxicity and antibacterial activity have been tested. The results show that the great cytotoxicity activity by ethyl acetate extracts which have an LC50 value is 123,718 µg/mL (R2 0.9822), while the great antibacterial activity shown by methanol extract 1,000 µg/mL with a diameter of inhibition zone 19.02 mm (S. aureus) and 16.06 mm (E. coli). 
Pembuatan Protokol Penapisan Virtual Berbasis Stuktur (pvbs) untuk Identifikasi Ligan Inhibitor Reseptor Platelet-Activating Factor (PAF-r) sebagai Target Terapeutik Asma menggunakan YASARA Nugraha, Gerry; Istyastono, Enade Perdana
Jurnal Riset Kimia Vol 11, No 1 (2020): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i1.346

Abstract

Platelet-activating factor receptors (PAF-r) is known as one of the receptors that affect asthma, while the Y-21480 ligand is reported as an effective, specific, and active PAF-r antagonist for asthma patients. Research in building structure-based virtual screening protocol (SBVS) for identification of PAF-r ligand inhibitors has been performed, the receptor crystal structure was obtained from the Protein Data Bank (PDB ID: 5zkp), while the ligand used as a leading compound is Y-24180, obtained from U.S. National Library of Medicine. Interactions between ligands and receptors are observed through molecular dynamics simulations using the YASARA program at intervals up to 20 nanoseconds, ligand-receptor binding stability occurs after a time interval of 2 nanoseconds, the lowest ligand-receptor binding energy occurs at a time interval of 1,401 picoseconds. Internal validation by re-docking 1,000 times the ligand to receptor resulted in a value of Root Mean Square Deviation (RMSD) of 0.6037 Å,  confirmed that SBVS protocol was accurately able to reproduce the Y-24180 ligand pose on the 5zkp crystal structure,  the protocol can be used as a new approach for investigation or design of compounds that have therapeutic potential as anti-asthma.
Validasi Metode MPM untuk Penentuan Kandungan Antioksidan dalam Sampel Herbal serta Perbandingannya dengan Metode PM, FRAP dan DPPH Yefrida, Yefrida; Suyani, Hamzar; Aziz, Hermansyah; Efdi, Mai
Jurnal Riset Kimia Vol 11, No 1 (2020): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i1.342

Abstract

The Modified Phenanthroline Method (MPM) has been validated for determination of antioxidant content in herb samples. Validation was done using Relative Standard Deviation (RSD) and percentage of recovery. The RSD and percentage of recovery for herb samples are 3.13% and 98.6%, respectively. Based on these values, MPM method is valid for determining antioxidant content in herb samples. T test shows no significant differences of antioxidant content using any of these methods, MPM, PM, FRAP or DPPH, at a 95% confidence level. MPM method shows a very strong correlation with PM and FRAP method.  While with DPPH and TPC shows is strong.
Kualitas Minyak Blend Kelapa Kopra dan Minyak Kelapa Sawit ditinjau dari Kadar Air, Kadar Asam Lemak Bebas dan Bilangan Peroksida Febliza, Asyti; Okatariani, Oktariani; Putri, Aisyah Meisya
Jurnal Riset Kimia Vol 11, No 1 (2020): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i1.347

Abstract

This research examined the quality of edible oil from Crude Coconut Oil (CCO) and Palm Coconut Oil (PCO) and their blends with CCO : PCO proportional was about 40:60 and 60:40, respectively. The quality of these samples was based on water proportion, free fatty acid (FFA) and peroxide value (PV) contained. This study was conducted to improve the quality of edible oil. SNI 3741-2013 was used as method of this research, which the result compared with the SNI standard for edible oil. Results of this research for water proportion in oil samples PCO, CCO, CCO (40) : PCO (60) and CCO (60):PCO  (40)  in  order  were  0.000122; 0.010905; 0.001878; 0.030996. The FFA proportions for them were 0.02; 0.01; 0.02; 0.02 and PV values were 7.10; 3.00; 6.10; 5.10, respectively. From this result, we can conclude that all samples had good quality for water proportion and FFA, except for peroxide value (PV) mark which had the higher mark compared to the SNI standard. We also concluded that CCO became the best quality of edible oil compared to others. 
Struktur dan Sifat Dielektrik Senyawa Aurivillius CaBi3LaTi4O15 yang Disintesis dengan Teknik Hidrotermal Zulhadjri, Zulhadjri; Amir, Firmanul Qadri; Mahmud, Marsal; Septiani, Upita; Arief, Syukri
Jurnal Riset Kimia Vol 11, No 1 (2020): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i1.343

Abstract

Synthesis of four-layer Aurivillius CaBi3LaTi4O15 has been successfully carried out by hydrothermal technique using NaOH 4 M as mineralizer. The reaction was carried out at 220 °C for 72 h. Crystal structure, morphology, and dielectric properties were analyzed in this study. X-ray diffraction confirmed that the single-phase product was successfully obtained. The refinement result shows the product has orthorhombic crystal structure with space group A21am. The morphology analyzed using SEM shows plate-like grains are observed, which is characteristic of Aurivillius phase. Dielectric curves show peaks at 585 °C which indicate ferroelectric transition temperature.
Penetapan Kadar Fenolik dan Flavonoid Hasil Ultrasonic Assisted Extraction Daun Binahong (Anredera cordifolia [Ten] Steenis) Sjahid, Landyyun Rahmawan; Aqshari, Amelia; Sediarso, Sediarso
Jurnal Riset Kimia Vol 11, No 1 (2020): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i1.348

Abstract

Anredera cordifolia [Ten] Steenis has been proven to have pharmacological activity that is thought to be influenced by the presence of phenolic compounds and flavonoids. However, both compounds are found in small concentrations through conventional extraction (maceration, decoction, soxhlet, and reflux). This study aims to prove that the ultrasonic assisted extraction method can obtain higher concentrations of phenolic and flavonoid compounds. Dried binahong leaves were extracted using ultrasonic assisted extraction with 70% ethanol. Phenolic levels were determined using Folin-Ciocalteu, while flavonoid levels were determined using the colorimetric aluminum method. The results showed binahong leaves ethanolic extract had phenolic levels of 10.16 % GAE and flavonoid levels of 10.58 % QE. These results are much higher than the results obtained using conventional extraction so that ultrasonic assisted extraction can be recommended to maximize the extraction of phenolic and flavonoid levels from the leaves of Binahong (Anredera cordifolia [Ten] Steenis). 
Adsorpsi Asam Humat pada Zeolit Alam yang Dimodifikasi dengan TiO2 Septiani, Upita; Tasari, Fiska Julian; Zilfa, Zilfa
Jurnal Riset Kimia Vol 11, No 1 (2020): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i1.344

Abstract

This research modified natural zeolite with TiO2 synthesized by the sol-gel process which was applied as a humic acid adsorbent. The purpose of this study was to coat natural zeolites with TiO2 to increase the adsorption capacity of natural zeolites as humic acid adsorbents. The natural zeolite powders were obtained from Kabupaten Solok, West Sumatra, based on X-ray Fluorescence (XRF) analysis, the ratio of silica/alumina (Si/Al) was 4.35, indicating that natural zeolite was clinoptilolite zeolite. Scanning Electron Microscopy (SEM) analysis showed natural zeolite has a rough surface with closed pores while zeolite coated with TiO2 (zeolite/TiO2) has a homogeneous, smooth surface with open pore. The results of the Energy Dispersive X-Ray Spectroscopy (EDS) analysis showed that the level of TiO2 was 7.1%, this result showed that TiO2 has been coated on the surface of the zeolite. Natural zeolite and zeolite/TiO2 were applied as humic acid adsorbents. Maximum adsorption capacity of natural zeolites and zeolites/TiO2 were 0.2787 mg/g and 1.199 mg/g, respectively.
Sintesis dan Karakterisasi Enkapsulat Katalis Nikel (II) pada Silika Mesopori Modifikasi Admi, Admi; Ramadhani, Fitria; Syukri, Syukri
Jurnal Riset Kimia Vol 11, No 2 (2020): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i2.356

Abstract

Ni(II)-BF3/MCM-41 was synthesized for heterogeneous catalyst. The boron trifluoride modified mesoporous silica BF3/MCM-41 was studied to investigate its ability as supporting agent in heterogeneous catalysis system. For this purpose, the structural directing agent remaining in as-synthesis MCM-41 removed by solvent extraction. Surface modification of mesoporous silica MCM-41 with aniline and boron trifluoride was carried out. Then, the surface of boron trifluoride modified mesoporous silica was subjected to an encapsulation with Ni(II) ions. These solid materials were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic absorption spectroscopy (AAS). In the FTIR spectra of the modified silica mesoporous, the presence of vibration band >Si-O-B confirm the success of modification of support. While, the shifting of the vibration band >Si-O-Si< is considered an indication of the proof of Ni(II) species onto the modified mesoporous silica. From the SEM photograph, it can be seen that the morphology of the Ni(II)-BF3/MCM-41 tend to form aggregates of smaller particles. Based on measurement of metal content by AAS, it was known that the value of metal loading is 33%. While for the leaching test, Ni(II)-BF3/MCM-41 lost only 0.014 % of Ni metal. It indicates the stability of the interaction between the N(II) and support of the modified mesoporous silica.

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